`R/calc_annual_cumulative_stats.R`

`calc_annual_cumulative_stats.Rd`

Calculates annual and seasonal total flows, as volumetric discharge or water yields, from a daily streamflow data set. For water year and seasonal data, the year is identified by the year in which the year or season ends. Two-seasons and four-seasons per year are calculated, with each 6 and 3-month seasons starting with the first month of the year (Jan for calendar year, specified for water year). Each season is designated by the calendar or water year in which it occurs. Calculates statistics from all values from complete years, unless specified. Returns a tibble with statistics.

```
calc_annual_cumulative_stats(
data,
dates = Date,
values = Value,
groups = STATION_NUMBER,
station_number,
use_yield = FALSE,
basin_area,
water_year_start = 1,
start_year,
end_year,
exclude_years,
months = 1:12,
include_seasons = FALSE,
transpose = FALSE,
complete_years = FALSE
)
```

- data
Data frame of daily data that contains columns of dates, flow values, and (optional) groups (e.g. station numbers). Leave blank or set to

`NULL`

if using`station_number`

argument.- dates
Name of column in

`data`

that contains dates formatted YYYY-MM-DD. Only required if dates column name is not 'Date' (default). Leave blank or set to`NULL`

if using`station_number`

argument.- values
Name of column in

`data`

that contains numeric flow values, in units of cubic metres per second. Only required if values column name is not 'Value' (default). Leave blank if using`station_number`

argument.- groups
Name of column in

`data`

that contains unique identifiers for different data sets, if applicable. Only required if groups column name is not 'STATION_NUMBER'. Function will automatically group by a column named 'STATION_NUMBER' if present. Remove the 'STATION_NUMBER' column beforehand to remove this grouping. Leave blank if using`station_number`

argument.- station_number
Character string vector of seven digit Water Survey of Canada station numbers (e.g.

`"08NM116"`

) of which to extract daily streamflow data from a HYDAT database. Requires`tidyhydat`

package and a HYDAT database. Leave blank if using`data`

argument.- use_yield
Logical value indicating whether to calculate area-based water yield, in mm, instead of volumetric discharge. Default

`FALSE`

.- basin_area
Upstream drainage basin area, in square kilometres, to apply to observations. Three options:

(1) Leave blank if

`groups`

is STATION_NUMBER with HYDAT station numbers to extract basin areas from HYDAT.(2) A single numeric value to apply to all observations.

(3) List each basin area for each group/station in groups (can override HYDAT value if listed) as such

`c("08NM116" = 795, "08NM242" = 10)`

. If group is not listed the HYDAT area will be applied if it exists, otherwise it will be`NA`

.- water_year_start
Numeric value indicating the month (

`1`

through`12`

) of the start of water year for analysis. Default`1`

.- start_year
Numeric value of the first year to consider for analysis. Leave blank or set well before start date (i.e.

`1800`

) to use from the first year of the source data.- end_year
Numeric value of the last year to consider for analysis. Leave blank or set well after end date (i.e.

`2100`

) to use up to the last year of the source data.- exclude_years
Numeric vector of years to exclude from analysis. Leave blank or set to

`NULL`

to include all years.- months
Numeric vector of months to include in analysis (e.g.

`6:8`

for Jun-Aug). Default summarizes all months (`1:12`

). If not all months, seasonal total yield and volumetric flows will not be included.- include_seasons
Logical value indication whether to include seasonal yields or volumetric discharges. Default

`TRUE`

.- transpose
Logical value indicating whether to transpose rows and columns of results. Default

`FALSE`

.- complete_years
Logical values indicating whether to include only years with complete data in analysis. Default

`FALSE`

.

A tibble data frame with the following columns, ending with '_Volume_m3' or '_Yield_mm' based on selection:

- Year
calendar or water year selected

- Total_*
annual (or selected months) total flow, in m3 or mm

Default seasonal columns:

- MMM-MMM_*
first of two season total flows, in m3 or mm

- MMM-MMM_*
second of two season total flows, in m3 or mm

- MMM-MMM_*
first of four season total flows, in m3 or mm

- MMM-MMM_*
second of four season total flows, in m3 or mm

- MMM-MMM_*
third of four season total flows, in m3 or mm

- MMM-MMM_*
fourth of four season total flows, in m3 or mm

Transposing data creates a column of 'Statistics' and subsequent columns for each year selected.

```
# Run if HYDAT database has been downloaded (using tidyhydat::download_hydat())
if (file.exists(tidyhydat::hy_downloaded_db())) {
# Calculate annual total volumetric flow statistics
calc_annual_cumulative_stats(station_number = "08NM116")
# Calculate annual total yield statistics with default HYDAT basin area
calc_annual_cumulative_stats(station_number = "08NM116",
use_yield = TRUE)
# Calculate annual total yield statistics with a custom basin area
calc_annual_cumulative_stats(station_number = "08NM116",
use_yield = TRUE,
basin_area = 800,
start_year = 1980)
}
#> Warning: One or more calculations included missing values and NA's were produced. If desired, filter data for complete years or months, or use the 'ignore_missing' or 'allowed_missing' arguments (if applicable) to ignore or allow some missing values.
#> Warning: One or more calculations included missing values and NA's were produced. If desired, filter data for complete years or months, or use the 'ignore_missing' or 'allowed_missing' arguments (if applicable) to ignore or allow some missing values.
#> # A tibble: 41 × 3
#> STATION_NUMBER Year Total_Yield_mm
#> <chr> <dbl> <dbl>
#> 1 08NM116 1980 212.
#> 2 08NM116 1981 302.
#> 3 08NM116 1982 333.
#> 4 08NM116 1983 310.
#> 5 08NM116 1984 290.
#> 6 08NM116 1985 198.
#> 7 08NM116 1986 250.
#> 8 08NM116 1987 113.
#> 9 08NM116 1988 180.
#> 10 08NM116 1989 215.
#> # … with 31 more rows
```